Harris concludes that the average hours spent online have increased from 7 hours from 1999 to 2002, to between 8 and 9 hours in 2003 to 2006, and surged after that.
There was a sudden spike in time spent online in 2007 when the average hours spent on the Web increased to 11 hours. Last year, Internet users were online for 14 hours a week, double what it was from 1999 to 2002, although Harris says this could have something to do with the outbreak of the financial crisis and the lead-up to the presidential election in October 2008.
The study is about personal time on line and is not inclusive of e-mail time. Based on that, we are talking about just short of 2 hours per day online on average. Here is the data that may be of service to you.
There are no real surprises here. I think the shock of the proliferation of the online life is wearing off. There are likely to be other spikes moving forward like the increase of use of the mobile web that will be the new measure of growth online. I suspect that if Harris did some polling around that there would be great interest in the trending. Maybe that will help us identify when the real “Year of Mobile” was or is to be.